LOS ANGELES -- The Dodgers activated Zack Greinke from the disabled list on Wednesday to start against the Nationals and placed right-hander Josh Beckett on the 15-day disabled list due to a left groin strain.
Beckett said he tweaked his groin covering first base in the third inning of his start Monday against the Nationals. The veteran was removed from the game after allowing four runs in three innings.
"It didn't get enough better," manager Don Mattingly said. "Plus he's had other little issues that hopefully we get a chance to get on top of, too."
Mattingly alluded to those other health issues after Beckett's start on Monday, but neither the manager nor the pitcher would elaborate. Beckett said he was healthy enough to pitch and did not use the injuries as an excuse for his 0-5 record and 5.19 ERA in eight starts.
"He's missing by two inches when he's trying to hit a corner," Mattingly said. "He's just barely missing. I know Josh thinks right now he has to hit every corner and can't leave anything over the plate. Josh is a control guy. If he's missing, there's something going on."
Beckett is the eighth pitcher to spend time on the disabled list this year for the Dodgers, joining Greinke, Chad Billingsley, Chris Capuano, Scott Elbert, Ted Lilly, Stephen Fife and Shawn Tolleson.
A month removed from surgery on a broken left collarbone, Greinke made his third start of the season Wednesday night. The right-hander hadn't pitched for the Dodgers since April 11, when Carlos Quentin charged the mound during a benches-clearing melee in San Diego and slammed into Greinke.
The Dodgers went 10-19 following Greinke's injury.
"We haven't played very well since that, honestly," Mattingly said.
Rookie Matt Magill will start Sunday against the Braves in place of Beckett. The right-hander has a 6.92 ERA in three starts since making his Major League debut April 27.
Austin Laymance is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.